The invention relates to a catchment net for rockfall catchment systems or the like, with a net consisting of mutually-engaging rings or the like, and carrying means supporting the net. The net is retained in position on the outside on at least two mutually-opposing sides by at least one peripheral cable and/or one tensioning cable in each case.
In a catchment net of the generic type according to Specification EP-A-0 679 437, in the first instance individual rings are manufactured, which consist of a wire with several windings. These rings are then encompassed by further rings, until what may be referred to as a ring-net is formed.
Such a net has proved its great value in practice. In the event of a fall of rock or scree into the net, it is possible, with the specified dimensions of the net for a limited amount of energy to be absorbed without the net tearing and without the stonefall, which is to be stopped, falling through the net.
The object of the present invention is to develop further a catchment net of the generic type, based on the existing catchment net referred to, in such a way that higher energy values can be absorbed by it with relatively low expenditure of effort on design and construction. It is further intended for existing catchment net structures to be subsequently equipped with this invention, in order to allow them likewise to absorb higher energy values. It is further intended that, in the event of failure (tearing) of the peripheral cables or tensioning cables as a result of overloading, the system as a whole should still fulfil its protective task.
This problem is resolved according to the invention in that additional connection elements are provided for, which connect the net on its outside and/or on its interior to the carrying means, such that the energy incurred when a rock or the like falls into the net will be absorbed.
With an embodiment of the catchment net according to the invention, it has transpired that with these additional connection elements a higher value of the energy incurred by the impact of stonefall can be absorbed, up to more than 30%, without the net tearing. These connection elements are easy to manufacture and can, with little expenditure or effort, be secured to the carrying means on the one hand and to or in the net on the other.
These connection elements have proven to be highly advantageous as a means of braking, which have the effect of imposing a defined stretching of the connection element at a corresponding tensile loading.